Ex-Formula 2 racer Fukuzumi, who set a new lap record at Fuji during qualifying for the season-opener, posted a time of 1m27.130s to put the #8 NSX-GT he shares with Tomoki Nojiri almost half a second clear of the opposition in the Q2 pole shootout.
The #12 Impul Nissan GT-R, the only car in the GT500 field carrying no success handicap, set the pace in practice in the hands of Daiki Sasaki and was also the car to beat in Q1, when Kazuki Hiramine set the benchmark time of 1m28.032s.
That time was just enough for Hiramine to edge out Nojiri, but the roles were reversed in Q2 as Sasaki could only manage a 1m27.620s, 0.490s down on Fukuzumi's time.
Third-fastest was the Bandoh Toyota GR Supra driven by Yuji Kunimoto, a further 0.068s behind Sasaki, with early pacesetter Jann Mardenborough making it an all-Yokohama second row in the Kondo Racing Nissan in fourth.
Heikki Kovalainen was fifth-fastest in the SARD Toyota followed by Ronnie Quintarelli in the #23 NISMO GT-R, the heaviest car in Q2 with its 50kg success handicap.
Completing the top eight were Kohei Hirate in the NDDP/B-Max Nissan and the remaining Yokohama runner, the Mugen Honda of Hideki Mutoh.
Not surprisingly, all six cars carrying fuel restrictors struggled on SUPER GT's most power-dependent circuit, and were all eliminated in Q1.
The closest to scraping through was Hiroaki Ishiura in the #38 Cerumo Toyota, which will start from ninth, followed by the two TOM'S GR Supras of Yuhi Sekiguchi and Nick Cassidy and the second #14 Cerumo car of Kazuya Oshima.
Naoki Yamamoto could only muster 13th in the #100 Team Kunimitsu Honda, while the points-leading #17 Real Racing Honda, the only car in the field carrying a stage three fuel restrictor, was 15th and last in the hands of Koudai Tsukakoshi, 1.6s off the pace.
GT300: Second pole for Inging
Inging Motorsport's Toyota 86 MC scored its second pole of the season in the hands of Kazuko Kotaka, who went almost four tenths clear of the field.
Yuichi Nakayama had topped his Q1 group in the #31 apr Toyota Prius PHV GR Sport, but teammate Koki Saga fell 0.385s short of Kotaka in Q2 and had to settle for second.
Third-fastest was Togo Suganami aboard the Motegi-winning LEON Racing Mercedes-AMG GT3, which is one of three carrying the maximum 100kg success handicap versus just 9kg and 15kg respectively the top two qualifiers.
Likewise shrugging off its 100kg of ballast was the works-entered Subaru BRZ in fourth, while the Saitama Toyopet Toyota GR Supra GT300 that won the season-opening race at Fuji was fifth-fastest despite its 75kg handicap and the Cars Tokai Dream28 Lotus Evora MC that won the second Fuji race was eighth with its 93kg penalty.
The championship-leading Gainer Nissan GT-R NISMO GT3 could manage only 11th, one place ahead of the ARTA NSX GT3 - which was fastest in its segment courtesy of Toshiki Oyu before slipping all the way to 12th in the hands of veteran teammate Shinichi Takagi.
Results to follow